The United States has demanded the immediate release of Christian pastor Youcef Nadarkhani, who is facing execution in Iran on charges of apostasy for refusing to recant his faith.

In a statement on Thursday, State Department deputy spokesperson Mark C. Toner said Washington was deeply concerned over reports that a provincial court had renewed the execution order for Nadarkhani. If carried out, it would be the first execution for apostasy in Iran since 1990.

Government persecution for simply following one's faith is common in Iran, where followers of many religious traditions face harsh treatment and severe violations of their religious freedom. There has been a dramatic increase in the arrest of adherents to the Bahai faith recently, as well as an increase in suppression of freedom of expression in all forms.

"We stand with religious and political leaders from around the world in condemning Youcef Nadarkhani's conviction and call for his immediate release," Toner said in the statement.